Method for producing layers of distended fibrous material



Jan. 18;v 1938. e; WEATHERED,

METHOD FOR PRODUCING LAYERSHOF DISTENDED FIBROUS MATERIAL Filed Jan..22, 1936 4 Shet-Sheet 1 Jan. 18, 1938.

G. C. WEATH E RED METHOD FOR PRODUCING LAYERS OF DISIENDEDFIBR OUSMATERIAL Filed Jan. 22, 1936 4 Sheets-Sheet 2 Jan. 18, 1938., G. Q-WEATHERED 2,105,711

IE THOD'FOR PRODUCING LAYERS OF DISTENDED FIBROUS MATERIAL Filed Jan.'22, 1956 4 Sheets-Sheet s Jan. 18, 1938. s. c. WEATHERED IET ODFQRrnonucmc LAYERS or DISTENDED FIBRQUS MATERIAL Filed Jan. 22, 19:56 4Sheets-Sheet 4 Patented Jan. 18, 1938- UNITED STATES PATENT OFFICE A 72,105,711 DIS- Celluioam Corporation, Chicago, 11].,

poration of Delaware Application. January 22, 1936, Serial No. 60,215

3Claims.

The method hereinafter described relates to the production of layers ofdistended fibrous material of the character set forth in the BryantPatent No. 1,740,280, issued December 17, 1929. The

5 product therein described is made from cellulose fibers which, mixedwith a high percentage of water in the form of a thin mix, are treatedwith a foaming agent, particularly saponin, and agitated, which resultsin the production of a foamy mass which after drying maintains the formof a loose or fluffy mass of fibrous materials adapted for numeroususes, particularly for insulating,

hospital use, sanitary bandages, and the like.

In the production of such material, it is cus- Q tomary to prepare athin mix, and after the same has been foamed by agitation to the desiredextent to discharge a layer thereof onto the moving wire of aFourdrinier machine, whereon the same is subjected to suction to removea portion of the liquid and thereafter fed through a drier, from whichthe material emerges in the form of a relatively thick and coherentlayerof light fiufiy distended fibrous material having a surface skin formedthereon by compacting of the surface fibers under suction, in which formthe layer is cut to the desired lengths and used for the intended vpurpose. The steps involved in' the production 01. such layers are setforth and described in the Bryant Patent No. 1,841,785, issued January19, E0 1932; the Bryant Patent No. 1,870,279, issued August 9, 1932; andthe Bryantv Patent No. 1,929,090, issued October 3, 1933.

In the general method involved in the production of distended fibrouslayers as set forth in the i5 foregoing patents, difliculty incommercial production has heretofore been experienced in maintaininguniformity in the thickness and density of the layer by reason of thefact thatheretofore means were not provided to definitely regulate thequani0 titles of fiber and saponin and water fed into the.

mixv or to precisely control the discharge of the mix onto the'wire ofthe Fourdrinler machine, and the present invention is directed to amethod for overcoming the dimculties above mentioned and it for securinggreater uniformityin the thickness and character of the resultingproduct under con ditions permitting rapid production of the material bya continuous operation. The present invention, therefore, is directedto59 the method provided for rapidly and uniformly feeding the fibrousmaterial in relatively small particles or masses; to the measuring ofthe fibrous material and the liquid mixing agents employed; to the stepsprovided for insuring a comll plete and uniionn'mixture of theconstituent materials prior to the discharge, and to the regulating ofthe discharge of the mix onto the wire of the Fourdrinier machine in theform of a layer of uniform thickness and homogeneous character.

Further objects and details of the invention will appear from adescription of the same in conjunctanks, the measuring valve, and theagitating tank;. I

Fig. 4 isan end view of the agitating tank with the discharge gate asviewed from line 4 of Fig. 3; Fig. 5 is a perspective view of one of therotary stirrers or paddles: a

Fig. 6 is an enlarged cross sectional view of the measuring valve formeasuring all charges of the mix;

Fig. 7 is a longitudinal section of the same on line I; and

Fig. 8 is an enlarged detail of the ratchet mechanism for controllingthe rotation of the measuring valve.

Referring first to the general method involved, as illustrated in Fig.1, the fibrous material is first of all subjected to a beating operationin a beater tank 20, which is provided with a circuitous channel 2|aflorded by anouter continuous wall 22 and an inner continuous wall 23.Across the channel thus formed extends a heater roll 24 which is rotatedby a pulley 25 and a belt 26 leading to a motor 21.

The fibrous material, in the form of 9. till slurry, containing about 5%fiber and 95% water,.

is acted upon in the heater for a period of time which may vary fromthirty minutes to two hours or more, depending upon the extent to whichit is desired to hydrate and gelatinize the fibers, but for mostpurposes the beating operation will continue for about an hour, inaccordance with the principles set forth and described in the BryantPatent No. 1,841,785, previously mentioned.

The mix is withdrawn from the beater through a pipe 28 leading to a pump29, which thereafter elevates the pulpthrough a pipe 00 to a headtank 3I, within which is located a stirrer or paddle provided for the purposeof maintaining the mix in a homogeneous condition.

r is fed outwardly and caught in a pail 33 carried. The pulp at thisstage has a known The'mix is fed down from the head tank to an expeller32, through which the pulp isfed and a predetermined portion of thewater expelled by compression in a manner well understood in the art.From the expeller the partially dried pulp by a truck 34. water contentwhich is important in the securing of uniformity in the mix procured asthe result of subsequent operations.

The mechanisms heretofore described are of standard construction and ofa character commonly employed in the paper making or other allied arts,so that a detailed description of each of said mechanism is notrequired.

The charge of material in the pail 33 is elevated by a cable 35 to anupper elevation in the building, wherein are located a pair of mixingtanks 38, which are duplicates, each 0! which is provided with adischarge pipe at leading to a common discharge pipe The arrangement isone which enables the operator to employ the mining tanks alternately hymng up a mix of. material in one of the seen while the other isdischarging, so that a continuous new of properly mixed material can beconstantly maintained.

the valvestem to be raised and lowered to seat or unseat the plug valveto as occasion may re- The valve stem I I is surrounded by a tubularshaft 46 which is carried by the hub 41 of a bevel ear 58. The tubularshaft is iournalled through a journal block 49 in the center of a bridgeplate or spider bll which spans the upper rim of the tank;

The tubular shaft is provided with paddles or beater bars 5!, and theouter end of the lowermost beater bar 52 is upturned to lie in closelyadjacent relation to the conical hopper bottom and serve as a scraperbar for preventing the material from adhering to the walls of the tank.

. 'Th'e fibrous material is discharged from the pail into the tank whichis under replenishment for the time being, and as the properly measuredquantity 0! material is being poured into the tank, a liquid solutionwhichconsists mainly of water with a charge of saponin supplied,thereto,

as a foaming agent is discharged through apipe 53, each of the tanksbeing supplied with one of such pipes, which unite in a three-way valvecasing 54 and connect with a header 'pipe 55 lead- Sng'to a meter 56having a supply pipe 51, through.

which the solution of water and saponin is'admitted in measuredquantities to unite with a measured quantity or flbrous-material'ofknownliquid content, so that by properly measuring out the amounts of fibrousmaterial andsapon'in solution, a mix of predetermined liquid contentwill be admitted to the tank and subjected to a.

' mixing or stirring action throughout the period of time required forthe discharge of previously mixed "material from the companion tank,with the result that a proper mix will be maintained at all times, whichis highly essential in securing uniformity in'the density and thicknessof the completed layer of distended fibrous material.

The mix, after being discharged through one of the pipes 31 and throughthe common discharge pipe enters a cylindrical measuring valve casing58, within which is located a shaft E9 carrying radially extending wingsor plates 0, four being shown in the present embodiment.

wall 6| which lies in closely adjacent relation to the surrounding wallof the casing, so that a pair of radial wings. or plates 60 with theconnect-- ing curving wall 6| constitute in effect a segment, andbetween the two segments thus formed are located open cavities 62 whichconstitute the pockets for the reception of charges of the mix, which byrotation' of the shaft 59 are carried around to the lower side of thevalve chamber and discharged through a discharge pipe 63 located abovethe first compartment of an agitator tank 84 presently to be described.

Elie ends of the pockets 62 in the measuring valve member are closed byhead walls as which rotate within recesses tit in head plates ticonstituting part of the valve casing, and in order to Adjoining platesare united by a curving outer afford. asharp cutting edge for shearingthe fi-' brous material, the leading wing or plate of each segment pairis provided with a cutting blade 3t 7 which coacts with a cutting blade69 located at the shoulder formed by the emergence of the T from end toend of the rotating valve, and the throat Hi likewise extends from endto end of the valve casing, with the pipe 38 centrally located todischarge into the chamber thus afiorded in thethroat, which permits theliquid and fiber to distribute itself equally from end to end or thecasing and to flow down into whichever oi the measuring pockets ismoving through the upper portion oiits rotation for the time being.

In order to allow air to be vented as the mix flows into the pocket, avent plug II is provided at a point closely adjacent the throat ill, sothat, as the'measuring valve rotates and the material is delivered intothe upwardly presented pocket,

the air will be ejected, permitting the pocket to fill upto the top,without cavities or open interstices therein, so that, when the chargeis cut oil by the shearing action of the knife blades, a measured chargeof predetermined amount will be carried downwardly to the dischargingposition.

The measuring valve is rotated by the mechanismshown in Fig. 8. Thisconsists of a ratchet wheel 12 keyed upon the shaft 59, which ratchetwheel cooperates with a" dog 13 carried between an outer lever arm '14and an' inner arm 15 connected bythe shoulder 16 with the. lever arm.The arms I4 and 15 are pivoted upon shouldered which arms'in unison arepivoted to the buter ends of links 18, the inner ends of which straddlean adjusting screw block 19 on an adjusting screw Oil journalled througha standard 8| and operable by a hand wheel 82. fflie links 18'cooperatewith lowerlinks 83 pivoted upon the lug 84.

The arms "support between them an arouate shield 85 which overlies theteeth on the ,hubs 'I'l freely mounted upon the shaft 59, each of thehubs being provided with any arm H desired degree. In Fig. 8, theposition assumed by the arm H at the end of its thrust to the right isindicated in dotted lines, from which it will be observed that theshield 85 in the position shown serves to out ch four of the teeth, and

to "that extent reduces the range of movement of the measuring valveupon each operation of the ratchet. The arm '14 is actuated by a link 86(Fig. 2) which connects with a rocking arm 81 actuated by a star wheel88, which in turn is rotated by worm gearing 89 driven by a motor 90.Any other suitable mechanism for imparting oscillations to the arm 14might be employed, but by adjusting the effective range of action of thedog 13 in the manner shown, it is possible to closely regulate thefeeding speed of the measuring valve so that the material will bedelivered to the tank 64 in uniform relation to its discharge onto thewire of the Fourdrinier machine.

The tank 64 in the form shown consists of an upper section 9|, and alower section 92, ar-

ranged in superposed relation and connected through a duct 93. Thisarrangement is desirable in that it conserves floor space, although thesame result would be obtained by an arrangement in which the twosections were aligned with one another or merged into a. single tank ofcorresponding length.

,In Fig. 3, the center portions of the tank sections are brokenaway,.but as indicated in Fig. 2, the lower tank section comprises tencompartments, and the upper section four compartments, which areseparated from one another by weirs 94, which as shown are ofprogressively reduced height from the intake end toward the dischargeend of each tank section. Each of the compartments thus formed isprovidedwith a group of stirrers, each in the form of upper andlowerpaddles 95, and 96 mounted upon a vertical shaft 91. -The upper andlower paddles stand in vertically spaced relation to one another, thespacing being greater in the deeper compartments and correspondinglyless as the depth of the compartments decreases toward the discharge endof the tank section. The lowermost paddles, however,

stand at a uniform height above the floor of the tank.

The four shafts for actuating a single group of stirrers standvertically in parallel aligned relation from side to side of the tankcompartment within which they are located, and the shafts are journalledthrough bridge bars 98, and are also provided with pulleys 99 and beltsso arranged that all of the shafts will be operated in unison. As shownin Fig. 1, power is imparted to the outermost shafts at one end ofadjoining groups through power belts IOI operated by ajdriving pulleyI02, which drives the v outermost shafts of adjoining groups, and thepower thus imparted is distributed to the next w .of power. '7

od of driving, however, is immaterial so long as provision is made forthe uniform rotation of all of -the'- stirrers in unison from a commonsource Each of the paddles is provided with blades I04 which extendoutwardly and terminate in rearwardly extending downturned wings l05,thearrangement being such as to produce a vortical motion within the liquidmix, which tends to draw the material toward the centenalthoughconstantly permitting the escape of some of the materialover the lowerweir and toward the discharge end of the tank.

The mix of materials is discharged fromfthe 'mixing valve into thebottom of. the firstcompartment in the upper tier. The last compartmentin the upper tier on the discharge side is provided with a wall I06above which E located a fiap valve I01 mounted on a shaft I08 operatedby a handle through a worm and gear arrangement I09, which enables thefiap'valve .to be elevated to afford the desired clearance above thewall I06.

The duct 93 discharges beneath the lower edge of thew'all I06 and intothe first compartment of the lower tier. The last compartment of thelower tier is provided with a curving bottomplate H0 which extends fromthe crest of the last weir downwardly'and forwardly and terminates in alip III which contacts the surface of the wirelI2 on the Fourdriniermachine, thus furvided with an adjustable face plate H9 which permitsthe clearance to be further regulated. Af er the layer of material hasbeen flowed onto the wire of the Fourdrinier machine, it is confined inthe form of a straight edged layer between deckle strips -l20, and asthe wire advances, this layer is subjected to the suction of vacuumboxes I2I and finally delivered across atransfer belt I22 into an ovenI23, where it is subjected to a drying process prior to its ultimatedelivery and severance into sections of the desired length. Theseoperations are described in the Bryant Patent No.'1,841,785, and neednot be here described in complete detail.

The mix thus measured out flows into the first compartment of the upperseries and fills the compartment to the level of the weir. .Thestirrers, being operated in unison throughout the differentcompartments, will cause rotation of the upper and lower paddles whichimpart a vortical movement tothe liquid inflowing into each of thecompartments in turn, and the movement thus imparted tends to draw theliquid mix toward the center of the vortex, but as the liquid rises tothe level of theweir, a portion thereof will escape into the nextcompartment, so that,

as the compartments become filled, there will be a constant overflowingof the weirs, at .a descend ing level, however, in each section of thetank, a portion of the liquid escaping over the weir and the remainderbeingdrawn back into the vortex, so that the material ineach-compartment will be repeatedly recirculated before a portionthereof overflows and escapes, and this operation will continuethroughout the upper and lower sections of the tank, thereby thoroughlyagitating and foaming the liquid mix and causing a thorough diffusionand distention of the fibrous particles which are held in distendedrelation by the minute bubbles composing the foam. so that by the timethe mix reaches the point of final discharge onto the wire of theFourdrinier machine a uniform stream of material may be maintainedat'the point of discharge anddeposited upon the wire of the Fourdriniermachine in the form of a layer of uniform depth and-uniform consistency. The layer thus deposited at the wet end of the wire will beconfined between the deckle strlps'and advanced by the Fourdrinier wire,which permits a portion-of the liquid to drain away and a portionthereof to be extracted by suction, which also has the effect of formingupon the surface a relatively thin tough paperlike skin, which in thecompleted product serves to maintain the sections in a relatively stifiand coherent condition, so that they may be ultimately cut tothe desiredsize for the intended By the employment of pulp of the desiredcharacter, and byu'egulating the fluidity of the same and the extent ofthe agitation to which it is subjected and the amount of the foamingagent employed, it is possible, within 'wide limits, to vary the'qualityand character .of the resulting product, including the degree ofdistention ofthe fibrous particles, and the softness or flufiiness ofthe product. It is thus possible to produce distended fibrous materialsof sumcient softness, fineness and distention to serve in hospital use,or for sanitary purposes, or to vary the treatment in such a way as tosecure a product of the, requisite firmness and stiffness to serve as aninsulating layer in buildings, refrigerating appliances, or under likeconditions where an insulating layer is required.

Although the method has been described with considerable detail, it isnot the intention,,un-'

less otherwise indicated in the claims, to limit the claims to theprecise method described, since modifications in detail maybe introducedwithout departing from the spirit of the invention.

taining contiguous pools of liquid mix having their surfaceszit-progressively lowerv levels, supplying measured quantities of fiberand liquid including a foaming agent to the first pool'of the series inthe amounts required to provide a mix of the desired consistency,constantly maintaining individual agitation in each of the pools to theextent required to cause foaming of the mixture and to separate andmaintain the fibers indistended relation within the. foamy mass, (118-charging. from each pool by overflow to the sur- 2,105,711 I My face ofthe next pool in the form of a broad even layer and discharging from thelast poolof the a series in the form of'a broad even continuously formwidth and thickness, which consists in maintaining contiguous pools ofliquid mix having their surfaces at progressively lower levels,supplying automatically measured quantities of fiber foamy condition.and to separate and,maintain the fibers in distended relation within thefoamy mass, discharging from each pool by overflow to the surface of thenext pool in the form of a broad even layer and discharging from thelast pool of the series in the form of a broad even continuouslyhorizontally advancing layer of uniform thickness, confining the sidesof the advancing layer to maintain a uniform width for the layer, andextracting liquid from the layer during its advancement to the extentnecessary to make the layer self-sustaining and capable of manipulation.

3. The method of producing a coherent layer of distended fibrousmaterial of substantially uniform width and thickness, which consists inmaintaining contiguous pools of liquid mix having their surfaces atprogressively lower levels, providing difl'erent sources of supply formeasured quantities of fiber and liquid including a foaming agentcombined in the amounts required to provide a mix of the desiredconsistency, delivering charges of said mix alternately from each ofsaid sources-to the first pool of the series and constantly maintainingindividual vortical agitation ineach of the pools to the extent requiredto cause foaming of the mix and to separate and maintain the fibers indistended relation within the foamy-mass, discharging from each pool byoverflow to the surface of the next pool in the form of a broad evenlayer and discharging from the last pool of the series in the form of abroad even form thickness, confining the sides of-the advancing layer tomaintain a uniform width for the layer, and extracting liquid from thelayer during its advancement to'the extent necessary to make the layerself-sustaining and capable of manipulation. V

, GEORGE C. WEA'I'HERED.

continuously horizontally advancing layer of uni-'

